EP1971271B1 - Multi-wire instrument, in particular for endoscopes - Google Patents

Description

The invention relates to a multi-wire instrument according to the preamble of claim 1.

Such and similar multi-wire instruments are used in particular for endoscopes, for example in applications as stone trap instruments for trapping bile or kidney stones. The individual wires form in their functional state in the distal functional section a functional wire mesh in the form of a wire basket. The wire basket may also have the function of a loop or filter unit. Typically, the distal functional portion can be drawn into a guide tube with the functional wire mesh folded together and moved out of it again under unfolding of the functional wire mesh. For this purpose, preferably a superelastic material is used for the individual wires. made of a NiTi alloy, such as nitinol.

In a common type of instrument, the individual wires are brought together proximally behind their distal functional portion and fixed to a proximally continuing, the shank portion of the instrument forming shaft wire of tube or Lizenmaterial, see for example the patent US 6,013,086 , In use, this type of instrument can lead to difficulties if, for example, the connection between the proximal ends of the functional distal distal strands and the distal end of the heddle wire tears unintentionally under traction during trapping of a stone.

As a remedy to do so in the published patent application DE 197 22 429 A1 proposed, the individual wires of the distal functional section through forming areawise axial slits of a solid or tubular blank wire which acts as a shank-side pull string in the unslit proximal area. The axial slit terminates at a distance, leaving a distal end stub in front of the distal end face of the wire blank, to which an eg spherical or hemispherical end element can be attached.

In the post-published disclosure DE 10 2004 055 375 A1 is also an integrally formed from a piece of pipe multi-wire unit described with several pieces of wire, in which the pipe section is divided by regional axial slits, the axial slots end leaving a distal wire connection area with suitably small axial distance, so that in the functional state of the multi-wire unit, the wire pieces, for example form a particulate functional wire mesh, and the distal wire connecting portion is formed into a substantially centerless front end termination.

In the post-published disclosure DE 10 2005 030 010 A1 there is described a stone trap basket unit in which the cup region is formed by wire pieces which are brought together at their distal end and fixed to a distal head having a predetermined breaking characteristic. This is to ensure that the headpiece releases the wire pieces at the distal end in case of overload in use, so that an undesirable, uncontrolled tearing of other joints avoided and / or a captured stone can be released again.

The Utility Model DE 89 04 213 U1 discloses a multi-wire instrument of the type mentioned in the form of a Lithotriptors with a collecting basket, which is formed by a plurality of outwardly extending extending Fangsträngen of wire material, which at the Fangkörbchenspitze run together and are connected to a tensile strand of several Zugdrähten, the Zugstrang consists of a two-stranded wire rope whose number of strands at least equal to the number of Fangstränge the Fangkörbchens, which are formed by deformed strands of the wire rope, from the wire rope to the Fangkörbchenspitze go through and there with their free ends attached to each other. At a proximal foot region of the catching basket, the strands of the wire rope are held together by a sleeve in which, in addition, the optionally remaining strands, which extend only in the shaft section, terminate distally. In a part of the shaft section which adjoins the root area of the catching basket proximally, the strands are entseilt from one another and run untwisted, as a result of which the tensile strand flexibility is to be increased. In the same way, the hedgehog-forming strands run untwisted in their catcher section and in their adjoining distal end region, wherein they are fixed with their free distal ends by soldering or clamping to form a kind of predetermined breaking point to each other.

In the Patent US 6,187,017 B1 discloses a Steinfangkorbinstrument with a specific Fangkorbgestaltung, in which each two pair-forming individual wires then cross over to the basket-forming portion in the distal direction initially to form a first crossing point, then radially apart again and then again merged to form a second intersection point crossing each other to then be fixed in the axial direction of impact on an atraumatic cylindrical closing body, wherein at the two crossing points of a wire both times under or over the other wire or once over and the other time under the other wire can lie. With their proximal end, the individual wires are fixed directly after their basket-forming section on a separate shaft body.

Especially for medical applications e.g. For kidney stone removal, the smallest possible cross-section or diameter is desired for the multi-wire instruments in order to be able to introduce them into corresponding tissue channels without difficulty. At the same time, the functional wire mesh provided by the individual wires must ensure the properties required for its function, in particular with regard to stability or strength and flexibility or rigidity.

The invention is based on the technical problem of providing a multi-wire instrument of the type mentioned, which can be implemented with relatively little effort and if necessary with comparatively small cross-section or diameter in its shaft portion and in which the risk is minimized that joints in undesirable Tear way in use.

The invention solves this problem by providing a multiwire instrument having the features of claim 1. In this multiwire instrument, the individual wires are fixed at the distal end directly to each other or to a distal end body by a respective breakage connection and extend integrally from the distal end to the proximal end portion of the multiwire instrument , wherein the shaft portion is formed by the individual wires gathered there and held together.

Since the individual wires are integrally formed from the distal end to the proximal end portion of the multiwire instrument, there is no further shank wire to which the individual wires are to be fixed and hence no joint of the proximal ends of the single wires to the distal end of a proximal shank portion. Rather, the individual wires in the corresponding area itself form the entire shaft section. This eliminates the risk that such joints tear in use under stress undesirably. Rather, the fact that the predetermined breaking connections are provided at the distal end of the individual wires, ensured that at these predetermined breaking points the individual wires defined at its distal end of the connection point can solve, so that the function wire mesh formed by the individual wires open at its distal end can. This allows, for example when used as Steinfangkorbinstrument a distal release of an already captured stone in case of overload, thereby avoiding that the instrument rips elsewhere and possibly remain parts of the instrument in the tissue and / or too large, trapped stone can not be released , Since the shaft portion is formed by the merged individual wires themselves, it can be realized with a comparatively small cross-section, which essentially corresponds to the sum of the individual wire cross sections.

According to the invention, the individual wires are twisted together in the entire shaft portion and thus distally to the transition into the granule-forming functional portion. This makes it possible to provide a highly loadable shaft section with a comparatively small cross section even without the use of additional aids such as guide or fixing sleeves or the like.

According to the invention, the individual wires are in a proximal to the predetermined breaking connections adjoining distal end portion are twisted together so that they rest along this twist to each other. This measure is provided in addition to the measure of distal to directly to the granule-forming functional portion continuous twist in the shaft portion and provides an increased load capacity of the predetermined breaking connection of the distal individual wire ends.

In an advantageous embodiment of the invention according to claim 2, the individual wires in the granule-forming functional section are untwisted, so that they form a corresponding wire basket there with untwisted in associated longitudinal planes extending Korbdrahtabschnitten.

In one embodiment of the invention according to claim 3, the distal end body includes a hemispherical or full spherical end member, thereby imparting desired atraumatic properties to the distal end of the instrument.

In one embodiment of the invention according to claim 4, the distal end body on a closing element for fixing the distal individual wire ends and a proximal to the end element subsequent protective sleeve, in which the individual wires are taken with its distal end. The protective sleeve may serve to provide the desired breaking strength of the distal individual wire ends with a desired strength, e.g. to give rise to a bending of the individual wires in a granule-forming functional state.

In an embodiment of the invention according to claim 5, the distal end-side twist of the individual wires is similar to that in the shaft portion, i. it has essentially the same twisting parameters, in particular a substantially equal pitch of the helical twisting windings.

In one embodiment of the invention according to claim 6, the individual wires are fixed with their proximal end directly to each other or to a proximal end body and / or received in the proximal end portion in a handle tube element. This realizes advantageous configurations of the multiwire instrument in its proximal end portion.

For the individual wires, as stated in claim 7, e.g. monofilament wire or stranded wire material usable.

Fig. 1

eine schematische Seitenansicht eines endoskopischen Steinfanginstruments mit abgenommenem Handgriff,

Fig. 2

eine detailliertere Seitenansicht eines vorderen Teils des Steinfangkorbinstruments von Fig. 1,

Fig. 3

eine Seitenansicht eines für das Steinfangkorbinstrument von Fig. 1 verwendbaren Mehrdrahtinstruments,

Fig. 4

eine detailliertere Seitenansicht eines hinteren Endbereichs des Mehrdrahtinstruments von Fig. 3,

Fig. 5

eine Seitenansicht eines hinteren Endbereichs eines modifizierten Mehrdrahtinstruments,

Fig. 6

eine detailliertere Seitenansicht eines Bereichs Y des Mehrdrahtinstruments von Fig. 3,

Fig. 7

eine detailliertere Seitenansicht eines vorderen Endbereichs X des Mehrdrahtinstruments von Fig. 3 mit halbkugelförmigem Abschlusselement und Schutzhülse,

Fig. 8

eine Ansicht entsprechend Fig. 7 für eine Variante mit der erfindungsgemäβen, zusätzlicher Verdrillung der Einzeldrähte im distalen Endbereich,

Fig. 9

eine Ansicht entsprechend Fig. 7 für eine Variante ohne Schutzhülse und mit kugelförmigem Abschlusselement,

Fig. 10

die Ansicht von Fig. 9 mit gebrochener Sollbruchverbindung eines der Einzeldrähte,

Fig. 11

eine Ansicht entsprechend Fig. 9 für eine Variante mit der erfindungsgemäβen, zusätzlicher Verdrillung der Einzeldrähte im distalen Endbereich,

Fig. 12

eine Ansicht entsprechend Fig. 9 für eine Variante mit halbkugelförmigem Abschlusselement,

Fig. 13

eine Seitenansicht einer Variante des Mehrdrahtinstruments von Fig. 3 mit proximalem Endbereich entsprechend Fig. 5 und distalem Endbereich entsprechend Fig. 9,

Fig. 14

eine Seitenansicht eines Rohzustands des Mehrdrahtinstruments von Fig. 13 in einem anfänglichen Fertigungsstadium,

Fig. 15

eine Seitenansicht entsprechend Fig. 13 für eine Variante mit vier statt zwei Einzeldrähten und

Fig. 16

eine Seitenansicht entsprechend Fig. 13 für eine Variante mit sechs statt vier Einzeldrähten.

Advantageous embodiments of the invention are illustrated in the drawings and will be described below. Only Ausführusformen with twisted in the distal end single torso are part of the invention. Hereby show:

Fig. 1

a schematic side view of an endoscopic Steinfanginstruments with removed handle,

Fig. 2

a more detailed side view of a front part of Steinfangkorbinstruments of Fig. 1 .

Fig. 3

a side view of one for the stone catcher instrument of Fig. 1 usable multi-wire instrument,

Fig. 4

a more detailed side view of a rear end portion of the multi-wire instrument of Fig. 3 .

Fig. 5

a side view of a rear end portion of a modified multi-wire instrument,

Fig. 6

a more detailed side view of a region Y of the multi-wire instrument of Fig. 3 .

Fig. 7

a more detailed side view of a front end portion X of the multi-wire instrument of Fig. 3 with hemispherical end element and protective sleeve,

Fig. 8

a view accordingly Fig. 7 for a variant with the inventive, additional twisting of the individual wires in the distal end region,

Fig. 9

a view accordingly Fig. 7 for a variant without protective sleeve and with spherical end element,

Fig. 10

the view of Fig. 9 with broken breakage connection of one of the individual wires,

Fig. 11

a view accordingly Fig. 9 for a variant with the inventive, additional twisting of the individual wires in the distal end region,

Fig. 12

a view accordingly Fig. 9 for a variant with a hemispherical end element,

Fig. 13

a side view of a variant of the multi-wire instrument of Fig. 3 corresponding to the proximal end region Fig. 5 and distal end region accordingly Fig. 9 .

Fig. 14

a side view of a raw state of the multi-wire instrument of Fig. 13 in an initial manufacturing stage,

Fig. 15

a side view accordingly Fig. 13 for a variant with four instead of two individual wires and

Fig. 16

a side view accordingly Fig. 13 for a variant with six instead of four individual wires.

Hereinafter, advantageous embodiments will be explained in more detail with reference to the drawings, in which identical or functionally equivalent elements are marked with the same reference numerals for ease of understanding. This in Fig. 1 Steinfangkorbinstrument shown has a per se conventional structure with a distal functional area 1 and a proximally adjoining shaft portion 2, which passes through a handle connecting pipe 3 at its rear end and forms a so-called draft tube section 4. Core component of such a Steinfangkorbinstruments, such as for endoscopic Bile or kidney stone removal is used is a multi-wire instrument, as in a realization of the invention in Fig. 3 is shown.

How out Fig. 3 can be seen, the multi-wire instrument shown there includes a distal functional portion 5, in which a plurality of individual wires 6, in the example shown two individual wires, in the functional state shown a granule forming functional wire mesh in the form of a basket or loop unit 7, which is suitable for capturing stones. The individual wires 6 are brought together at their distal end and connected to each other. Proximally, the individual wires 6 are twisted together following the functional section 5 and extend in this way in one piece up to a proximal end region 8 of the multiwire instrument. With their twisted region, they form the entire relevant shaft section 9 of the multi-wire instrument from the proximal end directly to the transition into the granule-forming functional section 5.

In a manner known per se, the multiwire instrument is in accordance with when used in Steinfangkorbinstrument Fig. 1 guided axially movably with its shank portion 9 in a flexible guide tube or guide tube 10, as in Fig. 2 for a front part of the stone catcher instrument of Fig. 1 shown in more detail. To the rear end of the guide tube 10 is as out Fig. 1 it can be seen, the handle connection pipe 3 coupled to which in turn in the usual way a not shown handle for actuating the Steinfangkorbinstruments can be connected. In Fig. 2 is the multi-wire instrument in his out of the guide tube 10 moved out to the front state in which the distal functional portion 5 is released from the guide tube 10 and consequently the individual wires 6 take their körbchen- or loop-forming functional state 7 there. From this state, the multi-wire instrument can be axially moved to a retracted state, in in which the guide tube 10 with its distal region receives the distal functional section 5 of the multi-wire instrument, with the individual wires 6 correspondingly folding together. From this retracted, folded state, the multi-wire instrument can then be moved out again under the formation of corbels or loops forming the individual wires 6 in the distal functional section 5 again to the front.

In the proximal end region 8, the shank portion 9 of the multiwire instrument formed by the twisted individual wires 6 is of Fig. 3 received in a grip sleeve 11 and the end flush by a hemispherical closing element 12 flush, as in the detailed view of Fig. 4 to recognize more clearly. In an in Fig. 5 In the variant shown, the twisted individual wires 6 are terminated at their proximal end without a receiving grip sleeve with a hemispherical end element 12a.

As can be seen from the above explanations, thus, the finished stone catching instrument of Fig. 1 from the multi-wire instrument of Fig. 3 and the guide tube 10 together with the attached handle connection tube 3 and the handle, not shown, wherein the shank portion 9 of the multiwire instrument extends through the guide tube 10 and the handle connection tube 3 and forms with its proximal end region 8 the pull tube section 4 of the stone trap instrument.

Fig. 6 shows in a detailed view the transition of the individual wires 6 from their corbellate or loop-forming bent, untwisted functional state in the distal functional section 5 directly to the proximally adjoining, twisted distal end region 9a of the shaft section 9.

Fig. 7 shows in more detail the distal end region X of the multiwire instrument of FIG Fig. 3 , As can be seen, the individual wires 6 are fixed with their distal ends 6a abutting a hemispherical distal end element 13, wherein these compounds are each designed as a predetermined breaking connection 15, ie the strength of these compounds is set to a predetermined maximum value. When the load on the predetermined breaking connections 15 of the distal individual wire ends 6a with the distal termination element 13 exceeds this maximum value in use, this connection 15 desirably breaks, so that one or more of the individual wires 6 with their distal end loosen and the functional wire mesh formed by the individual wires 6 loosen 7 opens distally. A captured stone can be easily released in the way again if it turns out that it can not be moved or crushed under normal load by the stone catching instrument.

Furthermore, a protective sleeve 14 surrounding the individual wires 6 in its distal end region is fixed on the distal end element 13 in a flush-mounted manner. With this protective sleeve 14, the predetermined breaking connection of the distal individual wire ends 6a on the distal end element 13 can be protected, above all, against stresses resulting from a radial bending apart of the individual wires 6 in their distal functional section, so that undesired premature breakage of these predetermined breaking connections 15 due to such stress effects is avoided ,

Fig. 8 shows a very advantageous variant of the example of Fig. 7 regarding the distal end region design. While in the example of Fig. 7 the individual wires 6 are brought together in the distal end region without twisting and guided in the protective sleeve 14 to the distal end element 13 are in the example of Fig. 8 the individual wires 6 from their distal functional portion 5 forward under twist brought together and guided in the protective sleeve 14 to the distal end element 13. The distal twisting of the individual wires 6 means in the presently used, conventional sense of this term that the individual wires along this twisting each other abutting each other continuously contiguous. This provides an additional load protection for the predetermined breaking connection 15 of the distal individual wire ends 6a at the distal end element 13. Preferably, the distal twisting of the individual wires 6 is realized in a similar manner to the proximal twisting of the individual wires 6 in the shaft section 9. In this case, the characterization "similar" means that the one or more helical turns are realized with substantially the same winding parameters for the two twists, in particular as regards the pitch and the outer diameter of the turns. In this case, the distal twist can be realized in the same direction or alternatively in the opposite direction to the twist in the shaft portion 9.

Fig. 9 shows a further variant for the design of the distal end portion X of the multi-wire instrument of Fig. 3 or any other multiwire instrument. In this variant, which is not part of the claimed invention, the individual wires 6 are untwisted and guided without distal protective sleeve to a spherical distal end element 13a and fixed thereto with its distal ends 6a to form the respective predetermined breaking connection 15.

Fig. 10 shows the view from Fig. 9 for a situation in which one of the individual wires 6 has loosened at its predetermined breaking connection 15 from the distal end element 13a due to an overload in the desired manner. Due to the broken connection 15a, the detached individual wire, and thus the cup / loop unit formed by the two individual wires in this example, can open altogether distally, thereby releasing, for example, an already trapped stone. For example, such an overload can be deliberately brought about, if it turns out that a captured stone can not be moved out or crushed and therefore released from the stone catcher instrument to be able to pull it out again without stone from a tissue channel.

Fig. 11 shows a variant of the invention Fig. 9 in which the individual wires 6 that are brought together from the distal functional section are twisted in their distal end region until the fixation of their distal ends 6a by the predetermined breaking connections 15 on the spherical end element 13a. This increases as in the example of Fig. 8 the strength of the predetermined breaking connections 15 in particular against bending of the individual wires 6 in their core / loop-forming distal functional section.

Fig. 12 shows a further variant for the design of the distal end portion of the multi-wire instrument according to the invention again for the case of two individual wires 6 corresponding to the multi-wire instrument of Fig. 3 , In this variant, the individual wires 6 are brought together from their distal functional section to the front for the flush fixation of their distal ends 6a by the respective predetermined breaking connection 15 on a hemispherical end element 13b.

Fig. 13 shows in a view accordingly Fig. 3 a not leanspruchte variant of the multi-wire instrument, in which the twisted in the shaft portion 9 individual wires in their proximal end region accordingly Fig. 5 are closed by the proximal end element 12a and correspondingly in its distal end region to the distal functional section 5 Fig. 9 untwisted to the spherical distal end member 13 a out and fixed thereto by the predetermined breaking joints 15 with their distal ends 6 a. According to the invention, the individual wires terminate distally likewise with a twist analogous to the exemplary embodiment of FIG Fig. 11 ,

The multi-wire instrument is relatively easy to produce, as shown below the example of the multi-wire instrument of Fig. 13 illustrated. Fig. 14 shows the multi-wire instrument of Fig. 13 in an initial manufacturing stage. As can be seen, the individual wires 6 are first fixed at their proximal end 6a by the predetermined breaking connections 15 on the spherical distal end element 13a and attached in their proximal end region by welding connection 16 to one another and / or with their proximal end ends to a proximal end element. Subsequently, the individual wires in the distal functional section are then bent into their desired configuration in order to form the required functional wire mesh and twisted in the proximal subsequent shaft section in the desired manner.

Fig. 15 shows a variant of Fig. 13 , in which the multi-wire instrument of four individual wires 6 instead of two individual wires is formed, ie in the distal functional portion forms in the functional state a wire basket 7a of the four straightened at 90 ° -Winkelabstand individual wires 6 instead of in the example of Fig. 13 consists of two individual wires formed basket / loop unit, and the shaft portion 9a consists of four twisted individual wires.

Fig. 16 shows another variant of Fig. 3 in which the multiwire instrument is composed of six individual wires 6 which in the distal functional section, when in the functional state, are bent at a 60 ° angular distance to a corresponding cup unit 7b and continued in the shaft section 9b in one piece to the proximal end of the multiwire instrument under twisting In the distal end region, they are untwisted (not stressed) or, alternatively, according to the invention, are also guided under twisting to the distal end element 13a and fixed there.

The embodiments shown and described above make it clear that the invention provides a multi-wire instrument that can be realized with relatively small cross-sections and minimizes the risk of breaking wire connections under load at undesired locations. This is partly due to the fact that the multiwire instrument is formed continuously from individual wires extending in one piece from the distal end to the proximal end of the multiwire instrument, which are twisted together in the shaft section and / or otherwise held to one another, e.g. by welding points, while they form in the distal functional portion in the functional state a required granule-forming functional wire mesh, e.g. also as a loop or filter unit. On the other hand, the individual wires are brought together in front of the distal functional portion at its distal end and fixed directly to each other or to a distal end body by a respective predetermined breaking, which is designed for a defined maximum load and tear in case of overload desirably, preferably also in its distal end between the granule-forming functional portion and the respective predetermined breaking connection are twisted.

The multi-wire instrument according to the invention consequently has no further longitudinal wire section, with which the individual wires would have to be connected, and thus also no wire connection points between its distal and proximal ends, so that there is also no danger of corresponding connection points tearing unintentionally. For the individual wires are preferably super elastic materials such as a NiTi alloy such as nitinol, but also for such applications common steel materials, etc. usable. Each individual wire may consist of monofilament wire material or stranded material as needed. Due to the structural change in the material, it is relatively easy to design the fixation of the distal individual wire ends to one another or to a distal closure body as desired as a predetermined breaking connection. Compared to multiwire instruments, in which the individual wires for the distal functional section are cut from a tube piece which acts as a shaft section in the adjoining proximal region, smaller cross sections or diameters can also be achieved in the shaft section and thus increased rigidity with the same nominal diameter in the multiwire instrument according to the invention. Thus, it can be seen that multi-wire instruments of the present invention, which are useful in stone trap instruments, can be readily manufactured with shaft outside diameters less than 2.0mm by twisting the continuous strands and perform the required functions, with the overall length of the multistring instrument typically being in the range from about one meter to several meters.

It will be understood that the invention is not limited to endoscopic applications but can be used in all medical and other fields in which multi-wire instruments with a functional wire mesh of individual wires are used.

Claims (7)

1. A multi-wire instrument, particularly for endoscopes, having

   - a distal functional section including a basket-forming functional section (5) in which several individual wires (6) form a small wire basket, where the wires extend in a basket-forming distance to each other in a bent-open condition and are guided together at a distal end (6) and connected with one another, in that they are fixed directly to one another or to a distal terminating body (13), while forming a respective predetermined breaking connection (15), and

   - a shaft section (9) extending between the distal functional section and a proximal end region (8) of the multi-wire instrument,

   - the individual wires extending in one piece from their distal end to the proximal end region (8) of the multi-wire instrument, and the shaft section (9) being formed by the individual wires combined there and held together,

   characterized in that

   - the individual wires (6) are mutually twisted in the entire shaft section to the basket-forming functional section (5), changing from the twisted distal end (9a) of the shaft section (9) while radially expanding into the basket-forming functional section (5), and

   - the individual wires (6) are twisted in a distal end region distally adjoining the basket-forming functional section and rest against one another along said twisting.
2. The multi-wire instrument according to claim 1, further characterized in that the individual wires are untwisted in the basket-forming functional section.
3. The multi-wire instrument according to claim 1 or 2, further characterized in that the distal terminating body contains a hemispherical or spherical terminating element (13, 13a).
4. The multi-wire instrument according to any of claims 1 to 3, further characterized in that the distal terminating body contains a terminating element (13), to which the distal individual wire ends are fixed, and a protective sleeve (14) proximally adjoining the terminating element, in which protective sleeve (14) the individual wires are held with a distal end region.
5. The multi-wire instrument according to any of claims 1 to 4, further characterized in that the twisting of the individual wires in the distal end region takes place in the same manner and is either in the same direction or in the opposite direction to their twisting in the shaft section.
6. The multi-wire instrument according to any of claims 1 to 5, further characterized in that the individual wires are fixed with their proximal end (6b) directly to one another or to a proximal terminating body (12), and/or in the proximal end region, are received in a grip tube element (11).
7. The multi-wire instrument according to any of claims 1 to 6, further characterized in that the respective individual wire consists of a monofil wire material or of a stranded wire material.

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